Major Obama Donors are Pepe, Two American brothers of a Mexican casino magnate who fled drug and fraud charges in the United States and has been seeking a pardon enabling him to return have emerged as major fund-raisers and donors for President Obama’s re-election campaign. An undated photograph of Juan Jose “Pepe” Rojas Cardona.

The casino owner, Juan Jose Rojas Cardona, known as Pepe, jumped bail in Iowa in 1994 and disappeared, and has since been linked to violence and corruption in Mexico. A State Department cable in 2009 said he was suspected of orchestrating the assassination of a business rival and making illegal campaign donations to Mexican officials.

When The New York Times asked the Obama campaign early Monday about the Cardonas, officials said they were unaware of the brother in Mexico. Later in the day, the campaign said it was refunding the money raised by the family, which totaled more than $200,000.

As recently as January of last year, one of Mr. Cardona’s brothers in Chicago, Carlos Rojas Cardona, arranged for the former chairman of the Iowa Democratic Party to seek a pardon from the governor for Pepe Cardona, according to prosecutors in that state. None was forthcoming.

Last fall, Carlos Cardona and another brother in Chicago, Alberto Rojas Cardona, began raising money for the Obama campaign and the Democratic National Committee. The Cardona brothers, who have no prior history of political giving, appeared seemingly out of nowhere in the world of Democratic fund-raising, Democratic activists said.

The money Alberto Cardona raised put him in the upper tiers of fund-raisers known as bundlers, according to a list released last month by the campaign. He and Carlos Cardona each gave the maximum $30,800 to the Democratic National Committee, and a lesser amount to a state victory fund. A sister, Leticia Rojas Cardona of Tennessee, donated $13,000 to the national committee, and another relative in Illinois gave $12,600, records show. There is no record of Pepe Cardona making a donation.

Although the two brothers live and work in Chicago, they maintain ties to Pepe Cardona in Mexico. Alberto Cardona operates an advertising agency in Mexico that has worked for political candidates backed by his brother, according to public records and Mexican news reports. Public records also show that the domain name for the Web site of a restaurant Pepe Cardona owns is registered to Alberto Cardona.